1. Field of the Invention
The present invention relates to a scanning probe microscopy cantilever holder which vibrates a cantilever having a probe at the top of the cantilever in the direction orthogonal to the surface of a sample and relatively scans the sample and the probe by a fine adjustment mechanism while detecting the interaction between the probe and the surface to control the distance for measuring the topography and physical properties of the sample surface, machining the sample surface, or moving substances on the sample surface by the probe, and to a scanning probe microscope using the cantilever holder.
2. Description of the Related Art
In a traditional scanning probe microscope, the base part at the end of a cantilever having a probe at the tip end thereof is fixed to a cantilever holder, and forcedly vibrated at the frequency near the resonance frequency of the cantilever by a vibrating module such as a piezoelectric device. The amplitude or phase at that time are measured by a displacement detecting module such as an optical lever mode. The sample is placed on a triaxial fine adjustment mechanism such as a cylindrical piezoelectric device.
The sample is brought close to the probe by a coarse adjustment mechanism, and then the probe and the sample are brought closer enough to each other by the triaxial fine adjustment mechanism. Physical force such as atomic force is then acted between the sample and the probe, the sample and the probe are brought closer to each other to intermittently contact with each other in response to the vibration of the cantilever, and contact force is acted on them. The atomic force or contact force vary the amplitude or phase of the cantilever.
The physical force such as atomic force and the intermittent contact force depend on the distance between the probe and the sample. The probe and the sample are brought close to the area where atomic force or contact force are acted, and they are scanned in the two-dimensional plane by the triaxial fine adjustment mechanism while controlling the distance between the sample and the probe so that the amplitude or phase of the cantilever are always kept constant. Thus, the topographic image on the sample surface is imaged. Furthermore, the detection of the physical action on the apex of the probe and the sample surface also allows the measurement of physical properties such as electrical properties or optical properties. The measurement by the scanning probe microscope is conducted in the atmosphere in many cases. For example, in the case of bio-samples such as cells, chromosomes, DNA, and proteins, a sample is altered when it is exposed in the atmosphere. Thus, in some cases, measurement is conducted while the cantilever is being vibrated in a solution such as a culture solution.
Here, the configuration of a scanning probe microscope of the related art will be described with reference to FIG. 9 (for example, see Patent Reference 1).
In this related art, alternating voltage signals are applied to a vibrator 102 to forcedly vibrate a cantilever 101 vertically to a sample 103, and the cantilever 101 is driven at the frequency near the resonance frequency. At this time, the amount of amplitude of the vibration of the cantilever is detected by a deffection detector 104. For the distortion detector 104, a displacement gage by the optical lever mode using a semiconductor laser is generally used. When a probe 101a at the top of the cantilever 101 is apart far enough from the surface, the cantilever 101 is vibrated at constant amplitude, and the deffection detector 104 detects the alternating voltage signal matched with the vibration of the cantilever 101. The alternating current signal detected by the deffection detector 104 is measured as a root-mean-square value of the alternating current signal of the deffection detector by an RMS (Root Mean Square) detector 105.
When the apex of the probe 101a is brought close to the surface of the sample 103, atomic force is generally acted between the probe 101a and the sample 103. The sample and the probe are brought closer to each other, and then intermittently contacted with each other in response to the vibration of the cantilever, and contact force is acted on them. The atomic force or intermittent contact force attenuate the amplitude. A certain amplitude value after attenuation is set as a target value to allow controlling the distance between the probe 101a and the sample 103. A Z-translation controller 106 and a feedback control system 107 drive the XYZ-translation unit 108, and the XYZ-translation unit 108 scans the plane of the sample 103 (in the XY-direction) by an XY-scan control part 109 while controlling the distance between the probe 101a and the sample 103 (in the Z-direction). Thus, a three-dimensional image of the surface of the sample 103 can be generated.
Moreover, for the scanning probe microscope driven in a solution is utilized for observing biosamples and organic thin film samples in a liquid (for example, see Patent Reference 2).
Patent Reference 1 Japanese Patent No. 3,266,267 (page 13, FIG. 3)
Patent Reference 2 Japanese Patent No. 2,936,311 (page 13, FIG. 1)